Process for manufacturing taper point surgical needles

ABSTRACT

A process for manufacturing wire or needles having a taper point. Needle or wire blanks are cut from a roll of wire and mounted to a carrier strip. The carrier strip and needles are moved through a succession of forming and trimming and grinding stations. The blanks are preferably rotated in the strip while being ground.

This is a continuation of application Ser. No. 08/429,446, filed Apr.27, 1995, now abandoned, which is a continuation of application08/146,681, filed Nov. 1, 1993, now U.S. Pat. No. 5,477,604.

TECHNICAL FIELD

The field to which this invention pertains is surgical needles, morespecifically, a method of manufacturing taper point surgical needles.

BACKGROUND OF THE INVENTION

Surgical needles and methods of manufacturing surgical needles are wellknown in the art. Surgical needles typically consist of a shaft-likemember, which may be curved or straight. The member has a distalpiercing point and a proximal end for mounting or receiving a suture.Surgical needles are typically classified as either taper-point needles,wherein the diameter of the shaft tapers to a piercing point, or cuttingedge needles wherein the needles have various cutting edges along withpiercing points to assist in penetrating various types of tissue.

Surgical sutures may be attached or mounted to the proximal ends ofsurgical needles in various ways. One common way is to have a channelformed into the proximal end of the needle. The channel end typically isdie-formed into a needle during the manufacturing process and consistsof a cavity. When a surgical suture end or tip is placed into thecavity, the channel end is hit with a die one or more times underpressure forcing the sidewalls closed tightly about the suture tip toprevent the suture from separating from the needle. The process ofmounting a suture tip to the proximal end of a needle is known in theart as swaging. Another manner in which a suture may be mounted to asurgical needle is by drilling a hole, commonly referred to in the artas blind hole, into the proximal end of the needle. This can be doneusing conventional mechanical drilling apparatuses or conventional laserdrilling apparatuses. The end or tip of a suture is then inserted intothe drilled hole and the section of the proximal end of the needlesurrounding the blind hole is swaged in a conventional manner bycompressing with various conventional dies. It is also known to mountsutures to surgical needles using conventional adhesives.

Surgical needles are conventionally manufactured from surgical gradealloys, such as surgical grade stainless steel, which are purchased frommanufacturers in the form of rod or wire. The rod is drawn into wire androlled onto a spool. The initial step in the manufacture of surgicalneedles is to remove the wire from the spool, degrease or clean ifrequired, and then cut the wire into sections known as needle blanks.Each blank will have a length greater than the length of the finishedneedle, since material will necessarily be removed from the blank duringthe needle manufacturing process.

A conventional process for manufacturing a taper point needle typicallyconsists of cutting wire into needle blanks and taking each needle blankand subjecting the blank to a series of grinding operations. This isconventionally done in the following manner. The needle blanks are fedinto a conventional belt\stone grinding machine where they are given adistal tip. The needles are then transported individually or in bulk toa conventional needle drilling station wherein the needles are drilledusing conventional carbide or tool steel drill bits to provide aproximal suture mounting cavity. The needles are then typicallydegreased and moved in bulk to a conventional belt/stone grindingmachine for the finish taper grind and then to a curving machine toproduce a conventional curved configuration. The needles are thencleaned, heat treated and may be electrochemically treated toadditionally finish the needles. The conventional process is a batchprocess requiring the handling of the needles in bulk containers totransport them to and from the various work stations. Needles may becomedamaged or intermingled during such bulk transfers. In addition, theneedles must typically be individually mounted in chucks in each machineat each work station. Although this chuck mounting step may in somecircumstances be automated, it is typically a time consuming, laborintensive operation.

One conventional method of manufacturing cutting edge needles consistsof initially cutting wire into blanks as described above. The distaltips of the needle blanks are then rotary swaged in a rotary swagingmachine to produce a conical point having a spud. The spud is nextpartially cut and the needle blanks are then moved to a belt/stonegrinder and mounted into chucks wherein the distal tip of each needleblank is given the final grind to create the necessary shape for bayonetclosed die forming. The needle blanks are then moved in bulk or by chuckto a die station where each needle blank is die-formed. The needleblanks are then subjected to a series of grinding operations in aconventional belt/stone grinding machine to produce the cutting edgeshape, for example, eight or more separate grinds. The needle blanksmust be removed from the chucks and remounted in chucks after and priorto each grinding step, typically by using a walking beam mechanism. Theextensive bulk and manual handling required by this process may resultin damage to the needles, including the dulling of the points. Inaddition, the needle machines used in the prior art processes areoperator dependent. Each operator tends to set up a machine differentlyresulting in variability in needle geometry and performancecharacteristics. Since surgical needles are quality control tested priorto release, the problems associated with the prior art processes tend toresult in a financial burden upon the manufacturer in that a significantamount of the needles produced may have to be rejected and destroyed.

The previously described processes are labor intensive and typicallyutilize low speed, low output equipment. The needles are typicallymanually handled and transferred in bulk containers between various workstations or machines. In addition, numerous grinding steps are usuallyrequired. Often, needles are damaged, including the dulling of needlepoints, due to the extensive handling and numerous grinding steps whichare present in these processes. It is known that grinding operations areby their very nature imprecise resulting in wide variations in thedimensions of the finished needles. This imprecision resultingly yieldsa significant degree of geometric variability.

Accordingly, what is needed in this art is a process for manufacturingtaper point needles which is efficient and substantially minimizesmanual handling and also minimizes grinding.

DISCLOSURE OF THE INVENTION

Therefore, it is an object of the present invention to provide a novelprocess for manufacturing taper point needles.

It is a further object of the present invention to provide a process forimproving the manufacture of taper point surgical needles by minimizingthe number of grinding operations which must be used.

It is a further object of the present invention to provide a taper pointneedle manufacturing process which can be automated as a substantiallycontinuous process, eliminating or minimizing the need for batchprocessing.

Accordingly, a process for manufacturing taper point surgical needles byprogressively working a needle blank is disclosed. The process of thepresent invention consists of the initial step of cutting needle blanksfrom a roll of wire and mounting the blanks in a carrier. The carriertransports the blanks to a succession of work stations. At an initialtrim station, the distal end of the needle blank is cut at an angle withrespect to the longitudinal axis of the needle blank on at least oneplane and two preferably opposed planes. Next the needle blank istransported to an optional work station where it is rotated, for example90° from its previous position in the carrier. Then it is moved to atleast one additional trim station where similar angulated cuts are madeto the distal end of the needle blank on the remaining uncut sections.Then each needle blank is moved to a grinding station wherein the needleblank is rotated about its longitudinal axis in the carrier as thedistal tip of the needle blank is ground with a high speed grindingwheel parallel to the longitudinal axis of the needle blank. The needleis then cleaned, heat treated and electrochemically treated. Thefinished needle is optionally siliconized.

Yet another aspect of the present invention is a method of manufacturinga taper point surgical needle by progressively forming a needle blank.The process consists of the initial step of cutting needle blanks from aroll of wire and mounting the blanks in a carrier. The carriertransports the blanks to a succession of work stations. At the initialwork station, the needle blank is coined in at least one conventionalclosed die having a cavity. Each needle blank is then moved successivelyto a trim station where flash is trimmed from the needle blanks using apunch and die. Optionally, the needle blank can be transported to one ormore additional coining and trimming stations. Then each needle blank ismoved to a grinding station wherein the needle blank is rotated aboutits longitudinal axis in the carrier as the distal tip of the needleblank is ground with a high speed grinding wheel parallel to thelongitudinal axis of the needle blank. The needle blank is then cleaned,heat treated, and electrochemically treated. The finished needle isoptionally siliconized.

Yet another aspect of the present invention is a method of manufacturinga wire member having a distal taper point by progressively forming awire blank. The process consists of the initial step of cutting wireblanks from a roll of wire and mounting the blanks in a carrier. Thecarrier transports the blanks to a succession of work stations. At theinitial work station, the wire blank is coined in at least oneconventional closed die having a cavity. Each blank is then movedsuccessively to a trim station where flash is trimmed from the needleblanks using a punch and die. Optionally, the blank can be transportedto one or more additional coining and trimming stations. Then each wireblank is moved to a grinding station wherein the wire blank is rotatedabout its longitudinal axis in the carrier as the distal tip of the wireblank is ground with a high speed grinding wheel transverse to thelongitudinal axis of the blank. The wire blank is then optionallycleaned, heat treated and electrochemically treated. The finished wiremember is optionally siliconized.

Still yet another aspect of the present invention is a method ofmanufacturing a wire member having a distal taper point by progressivelyworking a wire blank. The process consists of the initial step ofcutting wire blanks from a roll of wire and mounting the blanks in acarrier. The carrier transports the blanks to a succession of workstations. At the initial trim station, the distal end of the wire blankis cut at an angle with respect to the longitudinal axis of the wireblank on at least one plane and preferably two planes. Next the wireblank is transported to a station where it is rotated, for example 90°from its previous position in the carrier. Then it is moved to at leastone additional trim station where similar angulated cuts are made to thedistal end of the wire blank on the remaining uncut sections.Optionally, the needle blanks are moved to a top and bottom flatteningstation wherein top and bottom flat sides are formed. Then each wireblank is moved to a grinding station wherein the wire blank is rotatedabout its longitudinal axis in the carrier as the distal tip of the wireblank is ground with a high speed grinding wheel parallel to thelongitudinal axis of the needle blank. The wire blank is then optionallycleaned, annealed and electrochemically treated. The finished wiremember is optionally siliconized.

Yet another aspect of the present invention is a method of manufacturinga surgical needle or a wire member having a taper point. The methodcomprises mounting a needle blank or wire blank in a carrier and movingeach needle or blank to at least one trim station and trimming the blankin at least one plane. Then, the blank is move to a grinding stationwhere the blank is optionally rotated in the carrier while the needle isground parallel to the longitudinal axis of the blank.

Yet a further aspect of the present invention is a method ofmanufacturing a surgical needle or a wire member having a taper point.The method comprises mounting a needle blank or wire blank in a carrierand moving each needle or blank to at least one coin station and coiningthe blank. Then, the blank is move to a grinding station where the blankis optionally rotated in the carrier while the needle is ground parallelto the longitudinal axis of the blank.

Still a further aspect of the present invention is a method ofmanufacturing a taper point needle or a wire member having a taper pointwherein a plurality of needle or wire blanks is mounted to a carrier.The carrier is moved to a grinding station wherein the grinding means isorbitally rotated about each blank to form a taper point.

Still yet a further aspect of the present invention is a method ofmanufacturing a taper point needle or a wire member having a taper pointwherein a plurality of needle or wire blanks is mounted to a carrier.The carrier is moved to a trim station wherein the blank is trimmed orsheared in multiple planes to form a taper point.

Other features and advantages of the invention will become more apparentfrom the following description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow diagram illustrating a process of the present inventionwherein the distal end of the needle blank is trimmed prior to grinding.

FIG. 2A-2F illustrate a progression of cross-sectional perspective viewsof the needle blank after having been processed through each step of theprocess.

FIG. 3 is a perspective view of a needle blank after it has been cut bythe blank cutter/strip former machine; the needle blank is seen mountedin a section of carrier strip with the proximal end or tail bent.

FIG. 4 is a perspective view of a taper point needle produced by theprocess of the present invention.

FIG. 5 is a schematic of a layout of the equipment used to manufacture aneedle using the process of FIG. 1.

FIG. 6 is a schematic of a tail turn rotary grinding assembly; theneedle blank is rotated clockwise in the carrier strip while the rotarywheel grinder grinds the needle in a direction parallel to thelongitudinal axis of the needle blank.

FIG. 7 is a flow diagram illustrating an alternate process for formingtaper point needles wherein the needle blanks are coined and trimmedprior to the grinding step.

FIG. 8A-8E illustrate a progression of cross-sectional views of a needleblank after having been processed through each step of the process ofFIG. 7.

FIG. 9 is a perspective view of a needle blank after it has been cut bythe blank cutter/strip former machine; the needle blank is shown mountedin a section of carrier strip with the proximal end or tail bent.

FIG. 10 is a perspective view of a needle produced by the process ofFIG. 7.

FIG. 11 is a schematic of a layout of process equipment used tomanufacture a needle using the process of FIG. 7.

FIG. 12 is a schematic of a tail turn rotary grinding assembly; theneedle blank is rotated clockwise in the carrier strip while the rotarywheel grinder grinds the needle in a direction parallel to thelongitudinal axis of the needle blank.

FIG. 13 is a flow diagram illustrating a prior art process formanufacturing taper point needles.

FIG. 14A-14D illustrate a progression of cross-sectional views of aneedle blank after having been processed through each step of the priorart process of FIG. 12.

FIG. 15 is a perspective view of a needle manufactured by the prior artprocess of FIG. 12.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to FIG. 1, a flow diagram for a needle manufacturing processof the present invention is illustrated.

Initially wire 6 from roll 5 is fed by a conventional gripper/feedermachine 10 to blank cutter/carriage strip former machine 30. The roll 5is rotatably mounted in gripper feeder/10. Simultaneously, the carrierstrip 21 is fed from carrier strip roll 20, which is rotatably mountedin conventional gripper/feeder machine 25 to blank cutter/carriage stripformer machine 30. In blank cutter/carrier strip former machine 30, thewire 6 which is fed from gripper/feeder 10 is cut into lengths which areconventionally referred to as needle blanks 31. As the needle blanks 31are being cut, the blank cutter/carrier strip former 30 issimultaneously processing the carrier strip 21. The carrier strip 21typically consists of a steel strip known as a bandoleer. The strip willbe sufficiently thick, sufficiently wide and sufficiently flexible toeffectively move and retain needle blanks while being capable of beingdie punched and formed. Preferably the bandoleer is made of a flexiblemetal such as cold rolled steel and equivalents thereof. However, thebandoleer may also be made from polymeric materials such as engineered,reinforced polymers and equivalents thereof. The wire 6 being fed fromgripper/feeder 10 is cut into lengths which are conventionally referredto as needle blanks 31 within blank cutter/carriage strip former machine30. As the needle blanks 31 are being cut, the blank cutter/carrierstrip former 30 is simultaneously processing the carrier strip 21 in thefollowing manner. Carrier strip 21 is processed to receive needle blanks21 and to engage indexing controls within the various work stations. Thecarrier strip 21 is die cut, formed and crimped to produce a carrierstrip having indexing pilot holes 25 and crimps which form mounting tabs26 for receiving, engaging and holding needle blanks 31. A section ofcarrier strip 21 having needle blanks 31 mounted therein is seen in FIG.3. Then, needle blanks 31 are cut and inserted into the mounting tabs 26of carrier 21 by inserting the wire 6 into each tab 26 and then cuttingthe wire 6 to from a needle blank 31. The tabs 26 are then crimped toretain the needle blanks 31. The proximal ends 32 of the needle blanks31 are bent approximately 90° from the longitudinal axis of the needleblank 31 to form tails 33. If desired, the carrier strip 21 may be acontinuous endless carrier which is reused during the needlemanufacturing process. The strip would have the pilot holes 25 and tabs26 and needles would be removed from the endless carrier at a convenientstage of the process, and remounted to one or more additional carrierstrips. One skilled in the art will appreciate that the needle blanks 31may also be mounted to the carrier strip 21 by alternate methods, ifdesired although not preferred, including welding, clips, adhesives,snap fits, and the like. The bandoleer strip could, if desired bereplaced by a member comprising a lattice of two or more wires. Theblank cutter/carrier strip cutter machine 30 consists of severalmachines and operations as described below including a strip formingtool station 39, wherein the pilot holes 25 and tabs 26 are formed,strip preparation tool station 38 wherein the tabs 26 are opened, wirecut-off and strip crimping tool station 39 wherein wire is fed into tabs26 and blanks 31 are cut and formed, and tail bending station 39Awherein the proximal tail of the needle blank 31 is bent to facilitaterotation in the carrier strip 21.

Next, the carrier strip 21 having needle blanks 31 mounted therein ismoved by a conventional gripper feeder mechanism to first shear station40. Movement of the carrier strip to the work stations is indexed toprecisely align each needle blank 31 within any of the work stations inthe following manner. The carrier strip 21 has indexing pilot holes 25punched into the carrier strip 21 by the blank cutter/strip former 30.The pilot holes mate with pilots mounted at each work station whichengage the pilot holes. The pilots consist of a moveable pin whichextends into the pilot holes 25. The strip 21 is indexed by a strip feedwherein pilot pins enter, engage and lock the carrier strip 21 into aprecisely aligned position within a work station tool. Needle blanks 31may be mounted at different intervals along the carrier strip 21, forexample, from 0.5" to 1.0" intervals. Because of the spatial layout ofthe tooling, not every needle blank 31 is within a work station at agiven time. Some needles will be indexed into a particular work stationwhile other needles will be queued up waiting to enter work stations.

Shear station 40 consists of a conventional die and punch. The needleblank 31 is trimmed or sheared in station 40 by having the distal end 34of the needle blank 31 cut or sheared at an angle, preferably an acuteangle, with respect to the longitudinal axis of needle blank 31 along atleast one plane and preferably two opposite planes. The needle blankprior to entering shear station 40 will have a distal configuration asseen in FIG. 2A. The needle blank 31 exiting trim station 40 may have aconfiguration as seen in FIG. 2B. Next the needle blank 31 is moved tooptional station 50 where it is rotated as required to trim theremainder of the needle blank, preferably 90° in the carrier 21 as seenin FIG. 2C. If desired multiple trim stations may be used to form aneedle blanks 31 having more that four planes trimmed, for example,multiple trims may be used to form a needle blank having a distalcross-section which is n-polyhedral. Next carrier 21 and the needleblank 31 are moved to shear station 60 where the needle is trimmed alongthe remaining untrimmed opposed sides to produce a configuration asillustrated in FIG. 2D. If desired, the needle blank 31 can be trimmedonly one time to form a single trim plane; or, it may be trimmed morethan four times to form multiple planes. The needle blank 31 is thenmoved to the top and side flattening stations 70 and 75 where the needleblank 31 is appropriately formed by giving it flats. Then the needleblank 31 is moved to a tail turn rotary grind station 80. Referring toFIG. 6, tail turn rotary grind station 80 consists of a tail turningdevice 81 and preferably a pair of grinding wheels 85, although onegrinding wheel may be used. In a preferred embodiment, the device 81consists of pin 83 mounted to a rotating disc 82 which engages the tail33 and rotates the needle blank 31 about its longitudinal axis withinthe carrier strip 21 (see FIGS. 3 and 6). The distal end of needle blank31 is simultaneously ground to a tapered point by the grinding wheels85. The needle blank 31 and the wheels 85 are preferably moved withrespect to each other during the grinding. Each grinding wheel 85 hasone half of the profile of the desired taper point needle configuration.However, if desired a single grinding wheel may be used or conventionalgrinding wheels not having a contour may be used. The grinding wheel 85or wheels 85 may have an angular or other profile. For the sake ofclarity, only one grinding wheel 85 is seen in FIG. 6. As the needleblank 31 is turned by the device 81, the grinding wheels 85 grind thedistal end of the needle blank 31 parallel to the longitudinal axis ofthe needle blank 31. The needle blank 31 has a distal configuration asseen in FIG. 2E after exiting grinding station 80. The carrier strip 21and needle blank 31 are next transported to tail turn rotary grindstation 90 for processing similar or identical to that which occurs intail turn rotary grind station 80 using similar or identical equipment.The needle blank 31 will have a distal configuration as seen in FIG. 2Fafter having been processed in tail turn rotary grind station 90. Thetail turning and wheel grinding speeds will be sufficient to removematerial effective to produce the desired taper point configuration.This will depend on material types and sizes as well as grinding mediatype and wheel configuration. The grinding media will typically becoarser in the first grinding station and finer in the second oradditional grinding stations. Although not preferred, an alternatemethod of grinding useful in the process of the present invention is tomaintain the needle blank 31 in a fixed configuration in the carriersuch as by welding and to orbitally move grinding wheel 85 about theneedle blank 31. It will also be appreciated that equivalent materialremoval devices can be used including a shearing device similar inoperation to a pencil sharpener and the like.

The term "taper point" as used herein is defined to mean the distal endof a needle or needle blank (or wire member) having a taper profilewhich tapers from a maximum dimension to a distal minimum wherein thedistal point may have a variety of radii ranging from a piercing pointto the original diameter of the wire used to manufacture the needle orneedle blank (or wire member).

The carrier strip 21 and each needle blank 31 are then moved to theoptional multiple curving anvil stations 100, 110 and 120 where theneedle blank 31 is given a conventional curved configuration of asurgical needle. Next, the needle blanks 31 are optionally rotated inneedle blank rotation station 125 using conventional mechanical means torotate the blank 31 in tabs 26 of carrier 21 to facilitate, e.g.,rolling onto a spool. Then, the needle blanks 31 and the carrier strip21 are optionally washed in wash station 130. The needle blanks 31 andcarrier 21 are then rolled onto a conventional spool in a conventionalmanner using a conventional spooling apparatus. If desired the carrierstrip 21 containing needle blanks 31 may be cut into strips for furtherprocessing. Next, the spool or tray containing needle blanks 31 and thecarrier strip 21 is moved to optional spool heat treat station 140 wherethe needle blanks 31 are heated with or without a controlled gasenvironment in an oven at a sufficient temperature for a sufficientamount of time to effectively improve the mechanical strength of theneedle blanks 31.

Next, the spool or tray containing the carrier strips 21 and the needleblanks 31 are moved to an optional annealing apparatus 150 where theproximal ends of the needle blanks 31 are annealed. The needles areheated in a conventional annealing process at a sufficient temperatureand held for a sufficient length of time at that temperature toeffectively anneal the proximal ends of the needle blanks 31. One reasonannealing may be used is to improve swaging. Annealing apparatus 150consists of any conventional apparatus including a flame, conventionaloven, resistance heating, induction heating, etc.

Next, the carrier strips 21 containing needle blanks 31 are moved tolaser drilling station 160. Optionally, the needles are removed fromcarrier strip 21 and remounted to a second carrier strip. Preferably theneedle blanks remain on the carrier strip 21 and the strip 21 with theneedle blanks 31 is fed to the laser drilling apparatus. The needleblanks 31 mounted to the second carrier strip are fed to a laserdrilling apparatus wherein a suture mounting hole is drilled into theproximal end of each needle blank. The hole which is drilled by thelaser is commonly referred to as a blind hole. The suture mounting holeif desired may also be mechanically drilled or drilled through otherconventional methods including electron discharge techniques, etc. Theloose needle blanks 31 can then be additionally cleaned and the needleblanks may be mounted into an additional carrier. Then, the needleblanks 31 are optionally washed and may, if desired, be placed into anoptional electrochemical bath 170. The needle blanks 31 are maintainedin the bath 170 for a sufficient time to effectively finish the needleblank 31. The finished needles 180 are then removed from theelectrochemical bath 170, and washed if necessary. If desired, theneedles 180 may be siliconized at siliconizing station 190 by treatingthe needles 180 with conventional siliconizing materials in aconventional manner using conventional equipment, e,g., immersion in atank of siliconizing material.

If desired, the above-described process may be modified by having asingle trim step prior to grinding the needle blank. In addition, theprocess may also be modified by not rotating the needle in the carrierwhile grinding. In such a case, the grinding would be accomplished withthe grinder orbitally rotated about the needle blank. In yet anothervariation of the above described process, the needle is not ground, thepoint is formed by shearing or trimming in at least four planes to forma blank having a distal cross-section which is n-polyhedral.

An alternate process of the present invention is illustrated in FIG. 7.In that process wire 206 from roll 205 is fed by a conventionalgripper/feeder machine 210 to blank cutter/carriage strip former machine230. The roll 205 is rotatably mounted in gripper/feeder 210.Simultaneously, the carrier strip 221 is fed from carrier strip roll220, which is rotatably mounted in conventional gripper/feeder machine225, to blank cutter/carriage strip former machine 230. In blankcutter/carriage strip former machine 230, the wire 206 which is fed fromgripper/feeder 210 is cut into lengths which are conventionally referredto as needle blanks 231. As the needle blanks 231 are being cut, theblank cutter/carrier strip former 230 is simultaneously processing thecarrier strip 221. The carrier strip 221 typically consists of a steelstrip known as a bandoleer. The carrier will be sufficiently thick,sufficiently wide and sufficiently flexible to effectively move andretain needle blanks while being capable of being die punched andformed. Preferably the bandoleer is made of a flexible metal such ascold rolled steel and equivalents thereof. However, the bandoleer mayalso be made from polymeric materials such as engineered, reinforcedpolymers and equivalents thereof. The wire 206 being fed fromgripper/feeder 210 is cut into lengths which are conventionally referredto as needle blanks 231 within blank cutter/carriage strip formermachine 230. As the needle blanks 231 are being cut, the blankcutter/carrier strip former 230 is simultaneously processing the carrierstrip 221 in the following manner. Carrier strip 221 is processed toreceive needle blanks 231 and to engage indexing controls within thevarious work stations. The carrier strip 221 is die cut, formed andcrimped to produce a carrier strip having indexing pilot holes 225 andcrimps which form mounting tabs 226 for receiving, engaging and holdingneedle blanks 231. Then, needle blanks 231 are cut and inserted into themounting tabs 226 of carrier 221 by inserting the wire 206 into each tab226 and then cutting the wire 206 to form a needle blank 231. The tabs226 are then crimped to retain the needle blanks 231. The proximal ends232 of the needle blanks 231 are bent approximately 90° from thelongitudinal axis of the needle blank 231 to form tails 233. Referringto FIG. 9, a section of carrier strip 221 containing needle blanks 31 isseen. As mentioned previously in the description of the process of FIG.1, blank cutter/strip former 230 similarly consists of several workstations.

Next, the carrier strip 221 having needle blanks 231 mounted therein ismoved by a conventional gripper feeder mechanism to first coin station240. Movement of the carrier strip to the work stations is indexed toprecisely align each needle blank 231 within any of the work stations inthe following manner. The carrier strip 221 has indexing pilot holes 225punched into the carrier strip 221 by the blank cutter/strip former 230as seen in FIG. 9. The pilot holes 225 mate with pilots mounted at eachwork station which engage the pilot holes 225. The pilots consist of amoveable pin which extends into the pilot holes 225. The strip 221 isindexed by a strip feed wherein pilot pins enter, engage and lock thecarrier strip 221 into a precisely aligned position within a workstation tool. Needle blanks 231 may be mounted at different intervalsalong the carrier strip 221, for example, from 0.5" to 1.0" intervals.Because of the spatial layout of the tooling, not every needle blank 231is within a work station at a given time. Some needle blanks 231 will beindexed into a particular work station while other needle blanks 231will be queued up waiting to enter a work station. Coining station 240consists of a conventional closed cavity two-piece die set. The needleblank 31 is coined in station 240 by having the distal end 234 of theneedle blank 231 hit with the die forcing the material into the cavitiesof the dies. The needle blank 31 prior to entering coining station 240will have a configuration as seen in FIG. 8A. The needle blank 231exiting coining station 240 has a configuration as seen in FIG. 8B. Ifdesired, although not preferred, prior to coining station 240, theneedle blank 231 may be optionally coined in an open radius die, i.e., adie without a cavity. Next the needle blank 31 is moved to trim station250 where it is blanked with a punch and cutting die. The needle blank31 upon exiting trimming station 250 will have a configuration as seenin FIG. 8C. If so desired, the needle blank 231 may be progressivelyformed in additional optional coin and trim stations such as coinstation 390 and trim station 400 as seen in FIG. 7. The needle blank 231is then moved to the top and side flattening station 260 where theneedle blank 231 is given flat top and bottom sides. Then the needleblank 231 is moved to a tail turn rotary grind station 270. Tail turnrotary grind station 270 consists of a tail turning chuck 271 and a pairof grinding wheels 275. In a preferred embodiment the chuck 271 consistsof pin 272 mounted to a rotating disc 273 which engages the tail 233 androtates the needle blank 231 about its longitudinal axis within thecarrier strip 221 (see FIGS. 9 and 12). The distal end 234 of needleblank 231 is simultaneously ground to a tapered point by the grindingwheels 275. Each grinding wheel 275 has one half of the profile of thedesired taper point configuration. However, if desired a single grindingwheel 275 may be used or conventional grinding wheels 275 not having acontour may be used. The grinding wheel 275 or wheels 275 may have anangular or other profile. For the sake of clarity, only one grindingwheel 275 is illustrated in FIG. 12. As the needle blank 231 is turnedby the chuck, the grinding wheels grind the distal end 234 of the needleblank 231 parallel to the longitudinal axis of the needle blank 231. Theneedle blank has a distal configuration as seen in FIG. 8D after exitinggrinding station 270. The carrier strip 221 and needle blank 231 arenext transported to tail turn rotary grind station 280 for processingsimilar or identical to that which occurs in tail turn rotary grindstation 270 using similar or identical equipment, although the gritsizes of the grinding wheels may be finer. The needle blank 231 willhave a distal configuration as seen in FIG. 8E after having beenprocessed in tail turn rotary grind station 280.

The carrier strip 221 and needle blank 231 are then moved to themultiple curving anvil stations 290, 300, and 310 where the needle blank231 is given a conventional curved configuration of a surgical needle.Next, the needle blanks 31 may be optionally turned in the tabs 26sufficiently to effectively allow rolling the carrier 21 and needleblanks 31 onto a spool. Then, the needle blanks 231 and the carrierstrip 221 are optionally washed in wash station 320. The needle blanks231 and carrier 221 are then rolled onto a conventional spool in aconventional manner using a conventional spooling apparatus. If desired,the carrier strip may alternately be cut into strips for furtherprocessing. Next, the spool containing needle blanks 231 and the carrierstrip 221 is moved to optional spool heat treat station 330 where theneedle blanks 231 are heated with or without a controlled gasenvironment in an oven at a sufficient temperature for a sufficientamount of time to effectively make the needle blanks 231 more ductileand to improve their mechanical strength.

Next, the spool containing the carrier strips 221 and the needle blanks231 are moved to a annealing apparatus 340 where the proximal suturemounting ends of the needles are optionally annealed. The needles areheated in a conventional annealing process at a sufficient temperatureand held for a sufficient length of time at that temperature toeffectively anneal the needle blanks 231. Annealing apparatus 340consists of a conventional annealing apparatuses as previously describedincluding a flame.

Next, the carrier strips 221 containing needle blanks 231 are moved tolaser drilling station 350 where a suture mounting hole is drilled intothe proximal end of each needle blank 231. The hole which is drilled bythe laser is commonly referred to as a blind hole. Then, the needleblanks 231 are optionally placed into an electrochemical bath 360 andare maintained in the bath 360 for a sufficient time to effectivelyfinish the needle blanks 231. The finished needles 370 are then removedfrom the electrochemical bath 360. If desired, the needles 370 may besiliconized at siliconizing station 380 by treating the needles 370 withconventional siliconizing materials in a conventional manner usingconventional equipment, e,g., immersion in a tank of siliconizingmaterial.

If desired, the process of FIG. 7 may be modified by eliminating thetrim station after the initial coining station. In addition, the processmay also be modified by not rotating the needle in the carrier whilegrinding. In such a case, the grinding would be accomplished with thegrinder orbitally rotated about the needle blank. In yet anothervariation of the above described process, the needle is not ground andthe point is formed by shearing or trimming in at least four planes toform a blank having a distal cross-section which is n-polyhedral.

The above-described processes may also be used to manufacture wiremembers having ends with taper points. Typically the processes would beidentical wherein wire blanks would be cut from a spool of wire andprogressively formed as described above. The heat treatment and curvingsteps could be omitted depending upon the application. In addition, oneor more grinding steps could be omitted depending upon the nature andtype of wire stock utilized to make the wire blanks. Such processescould be used to manufacture, for example, semiconductor leads,fasteners, pins, etc.

The terms "coined" and "coining" as used herein are defined to meanforming or reshaping a metal member by applying sufficient pressure tothe member to effectively cause the metal to flow into a cavity or ontoa surface of a die and to thereby assume, in whole or in part the shapeof the cavity or the surface of the die.

The needle wires which can be used in the process of the presentinvention include conventional needle wires made from metals such as 300series stainless steel, 400 series stainless steel, or any other wirewhich can be formed including conventional or known alloys.

The diameter of the needle wire used in the process of the presentinvention will have a diameter which will depend upon the particularalloy used. For example, the needle wire may have a diameter rangingfrom 0.001 inches to about 0.100 inches. More typically, wires having adiameter of about 0.010 inches to about 0.080 inches may be used,preferably about 0.015 inches to about 0.080 inches. However, otherdiameters may be used. The length of the needle blank 31 will vary inaccordance with the type of needle which is being manufactured. Thelength of the needle blanks will vary in accordance with severalparameters including the wire diameter, desired finished length and thetype of needle.

The curving anvil machines used in the process of the present inventionare conventional curving machines which operate in a conventionalmanner. The curving anvil machines may consist of forming elementshaving the desired radii. The curving anvil machines are mounted to asupport frame.

The cleaning bath operates in the following manner. The carrier stripand needle blanks are placed into a reservoir containing a conventionalaqueous cleaning solution such as an aqueous solution of a conventionalnon-caustic detergent. A conventional ultrasonic transducer is mountedin the reservoir. A conventional ultrasonic generator drives thetransducer. The needle blanks and strips are rinsed and dried prior toremoval from bath using a clear hot water rinse followed by a highvelocity air flow.

A carrier strip cutter, if used in place of spooling, operates in thefollowing manner. As the carrier strip is fed into the carrier stripcutter, a conventional die and punch is used to cut the strip intopre-determined lengths.

The heat treatment apparatus operates in the following manner utilizingthe following cycle. Rolls of carrier containing needle blanks areplaced onto trays. The trays are then loaded into a conventional heattreatment oven. The oven is brought to a sufficiently high temperaturefor a sufficient length of time to effectively heat treat the needleblanks. The process cycle temperatures and times are conventional in theart for processing metals.

The annealing apparatus used in the present invention consists of aconventional apparatus as previously described. The laser drillingapparatus consists of any conventional laser system having sufficientpower and accuracy to effectively and repeatedly drill blind holes inneedle blanks or needles.

The electrochemical bath apparatus consists of a conventional anodicelectrochemical bath. Residence time of the needle blanks in the bathwill be sufficient to effectively remove any residual material which maybe present on the needle blank 31 to improve the surface finish. Thechemical composition of the bath and voltages are conventional in thisart. The electrochemical bath mixture comprises an aqueous, acidicmixture.

The electrochemical bath operates in the following manner. The needlesare placed upon a metal conveyor belt which transports the needlesthrough the aqueous bath for a sufficient amount of time at a sufficientvoltage to effectively remove residual material such as residual metalflash from the needle blanks, thereby forming the finished needles.

The coining stations, grinding stations and trimming stations utilizedin the process of the present invention will consist of punches and diesmounted to frames which are in turn preferably mounted to a unitaryforming machine (see FIGS. 5 and 11). It will be appreciated that inautomated progressive forming processes of the type described, a needleblank will be successively be moved through the various work stations.At any given time as a needle blank 31 enters a particular station therewill be other needle blanks entering a subsequent or previous stations.All of the stations are operating on different needle blanks atsubstantially the same point in time so that, for example, as the needleblank 31 is moved to the shear station 40 from the blank cutter/carriagestrip former 30, a needle blank 31 is being moved to the curving anvil110 from tail turn rotary grind station 90. The cleaning baths, thespool heat treatment stations, the annealing apparatuses, the laserdrilling apparatuses, and the electrochemical bath 170 are typically notmounted to the forming machine.

The forming machine 195 used in the process of FIG. 1 consists of acentral frame or base 196. Mounted to the base 196 are the various workstations which consist primarily of punches and dies and the grinders85. The punches and dies are powered in a conventional manner. Forexample, the work stations may be powered by a motor which powers aflywheel having a clutch which in turn transmits power to the workstations with shafts, spur gears and bullgears. The flywheel is alsoused to create motion to drive various elements in multiple directionsto facilitate the process, e.g., wheels are moved in and out along withguides, and other motions are utilized. The grinders 85 are powered byelectric motors. The blank cutter/strip former station 30 is seen toconsist of four individual stations including strip forming tool station37, strip preparation tool station 38 and wire cut-off and stripcrimping tool station 39 and tail bending unit 39A. A schematic of thelay-out of the forming machine 195 is seen in FIG. 6. Sufficient forceis exerted upon the dies by the punches to effectively coin the wireblanks at each coining station. The forces will depend on the wirematerial, wire diameter, tool configuration, die configuration, etc.Typically the forces will range from up to about 30 tons or more.However, it will be appreciated that the forces may vary higher or lowerdepending upon the configuration of the dies and the diameter andmaterial of the needle blank 31. The forming machine 195 will preferablyhave a modular configuration wherein various stations can be added,removed or interchanged as desired to vary the process.

A similar layout for the forming machine 410 used to manufacture needlesin the process of FIG. 7 is seen in FIG. 11. The forming machine 410will operate in a manner similar to that of machine 195. The formingmachine 410 has frame 415. The machines are identical except thatmachine 410 will have coining and trimming stations instead of shearstations. Mounted to the base 415 are the various work stations whichconsist primarily of punches and dies and the grinders 285. The punchesand dies are powered in a conventional manner. For example, the workstations may be powered by a motor which powers a flywheel having aclutch which in turn transmits power to the work stations with shaftsand bullgears. The grinders 285 are powered by electric motors. Theblank cutter/strip former station 230 is seen to consist of fourindividual stations including strip forming tool station 237, strippreparation tool station 238 and wire cut-off and strip crimping toolstation 239 and tail bending machine 239A. A schematic of the lay-out ofthe forming machine 410 is seen in FIG. 11. The forming machine 410 willpreferably have a modular configuration wherein various stations can beadded, removed or interchanged as desired to vary the process.

A process of the prior art for manufacturing taper point needlesillustrated in FIG. 13. In that process needle blanks 500 are cut from aspool of wire in blank cutting machine station 510 and placed into abulk container. A needle blank 500 prior to processing is illustrated inFIG. 14A. Initially, the blank 500 is given a rough distal taper pointin first belt driven grinding wheel machine 520 as illustrated in FIG.14B. The needle blanks 500 are then transferred in bulk and mounted intoindividual chucks in drilling machine 530. The needle blank 500 has aconfiguration as seen in FIG. 14C after the drilling operation inmachine 530. Next the needles are degreased at station 540 in aconventional degreasing apparatus. Then the needle blanks 500 are movedin bulk to machine station 550 wherein the final curved configurationgiven to each needle blank 500 and the final tip is ground onto theneedle blank (see FIG. 14D). The needle blanks are also give flat topand bottom sides at station 550. Then the needles are moved in bulk toconventional heat treatment station 570, anode polish station 580 andbatch siliconization station 590 to produce finished needles 600. Afinished needle 600 is seen in FIG. 15.

There are numerous disadvantages associated with the process of theprior art. The disadvantages include low manufacturing and processthroughput speeds, inconsistency and manufacturing tolerance variation.In addition, the prior art process may subject needles to processdamage, including point dulling. Another disadvantage is that theprocess equipment utilized in the prior art process tends to haveinherent process variability due to the equipment design. Furthermore,the prior art process requires frequent material transfer in the form ofloose needle blanks from machine to machine.

Although this invention has been shown and described with respect todetailed embodiments thereof, it will understood by those skilled in theart that various changes in form and detail thereof may be made withoutdeparting from the spirit and scope of the claimed invention.

We claim:
 1. A method for manufacturing a taper point surgical needlecomprising:mounting a plurality of surgical needle blanks to a flatcarrier strip, each surgical needle blank having a proximal angulatedend; and, moving each surgical needle blank to a rotary grinding wheeland simultaneously grinding the distal end of the surgical needle blankwhile rotating the surgical needle blank in the carrier strip byengaging the proximal end of the surgical needle blank with a rotatingmeans to form a taper point.